1. Field of the Invention
This invention relates to an imaging apparatus comprising a solid image sensor adapted to be switched from the interlaced read out mode to the all pixels progressive read out mode or vice versa for imaging operations.
2. Related Background Art
Known imaging apparatus conforming to the established television standards such as the NTSC (National Television Systems Committee) standards or the PAL (Phase Alternation by Link) standards are adapted to obtain an imaging signal and output it as video signal conforming to specific set of television standards. A so-called cam-corder such as a video cassette recorder (VCR) or a video tape recorder (VTR) that is integral with a camera deal with a moving picture in the form of a video signal generated from an interlaced imaging signal and conforming to the specific television standards. When dealing with a still picture by the cam-corder, the interlaced signal is converted into a progressive scan signal for recording/reproducing the still image because a frame of picture is formed by two fields for the imaging signal obtained by an interlaced read out operation and the time lag between the two fields can degrade the picture.
With an electronic still camera exclusively designed for taking still pictures, a high image quality still picture imaging signal is obtained from the solid image sensor thereof that is adapted to progressive scanning by an all pixels progressive read out operation and then recorded on a recording medium.
However, known cam-corders are only adapted to the interlaced read out mode and hence cannot obtain an imaging signal adapted to both the interlaced read out mode and the all pixels progressive read out mode (hereinafter referred to the all pixels read out mode).
Therefore, it is an object of the present invention to provide an imaging apparatus adapted to be switched from the interlaced read out mode to the all pixels read out mode or vice versa for taking a still picture or a moving picture.
Another object of the present invention is to provide an imaging apparatus that is free from producing a jittering or otherwise disturbed picture as imaged output when switching from the interlaced read out mode to the all pixels read out mode or vice versa for operation.
Still another object of the present invention is to provide an imaging apparatus that is free from producing a jittering or otherwise disturbed picture as imaged output when switching from a mode of operation to another.
A further object of the present invention is to provide an imaging apparatus that is free from discrepancy between a still picture taken in the all pixels read out mode and a corresponding picture output for display.
According to the invention, the above objects are achieved by providing an imaging apparatus comprising a solid image sensor adapted to be switched from the interlaced read out mode to the all pixels read out mode or vice versa for outputting an imaging signal, an imaging signal processing means fed with the imaging signal from said solid image sensor, a scan conversion means for converting the imaging signal read out from said solid image sensor in the all pixels read out mode into an interlaced signal, an output signal processing means fed with the imaging signal from said imaging signal processing means or said scan conversion means and a control means for controlling the mode of operation of said solid image sensor and the operation of switching the input to said output signal processing means, the imaging signal read out from said solid image sensor in the interlaced read out mode being fed to the output signal processing means by way of the imaging signal processing means without any processing operation, the imaging signal read out from said solid image sensor in the all pixels read out mode being converted into an interlaced signal by said scan conversion means before being fed to said output signal processing means.
In an imaging apparatus according to the invention, preferably, said scan conversion means has a first memory means for storing the imaging signal read out from said solid image sensor in the all pixels read out mode and converts the imaging signal into an interlaced signal by way of said first memory means.
In an imaging apparatus according to the invention, preferably, said output signal processing means has a second memory means for storing the supplied imaging signal and outputs the imaging signal stored in the second memory means.
In an imaging apparatus according to the invention, preferably, said control means is adapted to control said output signal processing means at the time of switching the mode of operation of said solid image sensor from the interlaced read out mode to the all pixels read out mode so as to make it store the imaging signal immediately before the switching operation into said second memory means as output.
Preferably, an imaging apparatus according to the invention further comprises a still picture recording means for recording the imaging signal stored in said first memory means as still picture on a removable recording medium, said control means controlling the operation of writing an imaging signal in or reading it out from said first and second memory means so as to make the imaging signal to be recorded by said still picture recording means by way of said first memory means and the imaging signal stored in said second memory means as output by said output signal processing means agree with each other when recording the still picture by said still picture recording means.
Thus, in an imaging apparatus according to the invention, the solid image sensor is adapted to be switched from the interlaced read out mode to the all pixels read out mode or vice versa and the imaging output from the solid image sensor is processed by the common imaging signal processing means. Then, the imaging signal is output from the imaging signal processing means directly by way of the output signal processing means if it is read out in the interlaced read out mode, whereas the imaging signal is converted into an interlaced signal by the scan conversion means, which is subsequently output by way of the output signal processing means, if it is read out in the all pixels read out mode. Thus, the mode of operation of the solid image sensor is appropriately switched from the interlaced read out mode to the all pixels read out mode or vice versa for imaging and the obtained imaging signal is output by way of the output signal processing means that is particularly adapted to the interlaced read out mode.
Additionally, in an imaging apparatus according to the invention, preferably, said scan conversion means has a first memory means for storing the imaging signal read out from said solid image sensor in the all pixels read out mode. Then, it converts the imaging signal into an interlaced signal by way of said first memory means.
Still additionally, in an imaging apparatus according to the invention, preferably, said output signal processing means has a second memory means for storing the supplied imaging signal. Then, it outputs the imaging signal stored by way of the second memory means. Therefore, for example, when the mode of operation of said solid image sensor is switched from the interlaced read out mode to the all pixels read out mode, the imaging signal of the picture immediately before the switching operation can be stored in the second memory means as output in order to prevent the apparatus from producing a jittering or otherwise disturbed picture as imaged output at the time of switching the mode of operation.
Furthermore, an imaging apparatus according to the invention preferably also comprises a still picture recording means for recording the imaging signal stored in said first memory means as still picture on a removable recording medium. Then, said control means controls the operation of writing an imaging signal in or reading it out from said first and second memory means so as to make the imaging signal to be recorded by said still picture recording means by way of said first memory means and the imaging signal stored in said second memory means as output by said output signal processing means agree with each other when recording the still picture by said still picture recording means.